Endoscopic instruments with which a material removal can be carried out in a difficultly accessible cavity are known in the medical as well as in the technical field. With regard to these instruments, in the context of the invention, it can be the case of endoscopes as well as auxiliary instruments which are applied in combination with endoscopes.
Endoscopes of this type which are also called technoscopes or boroscopes, and which are predominantly provided for repair work on turbine blades in turbine engines are described for example in DE 42 41 767 C1 and DE 195 37 812 C1. These endoscopes in each case compromise an elongate hollow shank with observation optics which are arranged therein and which are optically connected to an eyepiece or camera connection, wherein this eyepiece or camera is arranged at the proximal side of the hollow shank. A tool which is designed for the removal of material is arranged at the distal end of the hollow shank. The material removal is effected by way of a rotation of the tool about its middle axis. This rotation is produced by way of an electric motor which is arranged on a housing connecting proximally to the hollow shank. The movement transmission from the motor shaft of the motor to the tool is effected via a belt drive, wherein the motor shaft is connected via a positive-fit coupling to a drive disc of the belt drive.
The endoscopes which are known from DE 42 41 767 C1 and DE 195 37 812 C1 have proven their worth on application, but it has be found that the assembly of the motor on the endoscope and hereby in particular the creation of the positive connection of a coupling half on the motor shaft side to a coupling half formed by the drive disc of the belt drive is comparatively cumbersome and demands significant manual skill on the part of the user.